The coal combustion in cast-iron stoves leads to health hazards and air pollution.In this study the CO,SO2,NOx,PM and VOC emission concentrations were measured whilst combusting four fuel particle sizes(15,20,30,and 4...The coal combustion in cast-iron stoves leads to health hazards and air pollution.In this study the CO,SO2,NOx,PM and VOC emission concentrations were measured whilst combusting four fuel particle sizes(15,20,30,and 40 mm)as well as a composite of the sizes(all pre-devolatilized at a temperature of 550C)in a cast-iron stove.The results were compared to their raw coal analogues to evaluate the emission performance of each fuel type.Emission factors for NOx and SO2 were found to depend on the fuel nitrogen and sulphur contents in the coal and the combustion conditions used during pyrolysis.The PM,SO2 and VOC emissions show a strong dependence on the ash percentage and volatile matter yields,which both increased with increasing particle size.In addition,the PM,SO2 and VOC missions were found to only depend on particle size on a mechanistic level.The VOCs and PM emission factors are inversely correlated with particle size.The results from this study offer insight into the combustion environment in the Falkirk Union No 7 cast-iron stove as well as how this environment applies to low smoke fuels.The work contributes to the emission and performance inventories from South African domestic coal combustion in this stove used in informal settlements.展开更多
The interfaces between the inorganic metal oxide and organic photoactive layer are of outmost importance for efficiency and stability in organic solar cells(OSCs).Tin oxide(SnO_(2))is one of the promising candidates f...The interfaces between the inorganic metal oxide and organic photoactive layer are of outmost importance for efficiency and stability in organic solar cells(OSCs).Tin oxide(SnO_(2))is one of the promising candidates for the electron transport layer(ETL)in high-performance inverted OSCs.When a solution-processed SnO_(2)ETL is employed,however,the presence of interfacial defects and suboptimal interfacial contact can lower the power conversion efficiency(PCE)and operational stability of OSCs.Herein,highly efficient and stable inverted OSCs by modification of the SnO_(2)surface with ultraviolet(UV)-curable acrylate oligomers(SAR and OCS)are demonstrated.The highest PCEs of 16.6%and 17.0%are achieved in PM6:Y6-BO OSCs with the SAR and OCS,respectively,outperforming a device with a bare SnO_(2)ETL(PCE 13.8%).The remarkable enhancement of PCEs is attributed to the optimized interfacial contact,leading to mitigated surface defects.More strikingly,improved light-soaking and thermal stability strongly correlated with the interfacial defects are demonstrated for OSCs based on SnO_(2)/UV cross-linked resins compared to OSCs utilizing bare SnO_(2).We believe that UV cross-linking oligomers will play a key role as interfacial modifiers in the future fabrication of large-area and flexible OSCs with high efficiency and stability.展开更多
Polymer solar cells(PSCs)with high power conversion efficiency(PCE)and environment-friendly fabrication are the main requirements enabling their production in industrial scale.While the use of non-halogenated solvent ...Polymer solar cells(PSCs)with high power conversion efficiency(PCE)and environment-friendly fabrication are the main requirements enabling their production in industrial scale.While the use of non-halogenated solvent processing is inevitable for the PSC fabrication,it significantly reduces the processability of polymer donors(PDS)and small-molecule acceptors(SMAs).This often results in unoptimized blend morphology and limits the device performance.To address this issue,hydrophilic oligoethylene glycol(OEG)side-chains are introduced into a PD(2EG)to enhance the molecular compatibility between the PD and L8-BO SMA.The 2EG PD induces higher crystallinity and alleviates phase separation with the SMA compared to the reference PD(PM7)with hydrocarbon side-chains.Consequently,the 2EG-based PSCs exhibit a higher PCE(15.8%)than the PM7-based PSCs(PCE=14.4%)in the ortho-xylene based processing.Importantly,benefitted from the reduced phase separation and increased crystallinity of 2EG PDS,the 2EG-based PSCs show enhanced thermal stability(84%of initial PCE after 120 h heating)compared to that of the PM7-based PSCs(60%of initial PCE after 120 h heating).This study demonstrates the potential of OEG side-chain-incorporated materials in developing efficient,stable,and eco-friendly PSCs.展开更多
The fibred magnesium hydroxide from the bracite was treated with a surface active agent. The modified fibred magnesium hydroxide as flame-retardant, boric acid, barium stearate, polydimethyl siloxane fluid, vinyltrie...The fibred magnesium hydroxide from the bracite was treated with a surface active agent. The modified fibred magnesium hydroxide as flame-retardant, boric acid, barium stearate, polydimethyl siloxane fluid, vinyltriethoxysilane as synergists of the flame-retardant were added to polyene resin. The flame-resistance polyene material prepared meets the requirements of EWCZ-6287-1. (Author abstract) 2 Refs.展开更多
Comprehensive Summary,Non-halogenated polymers have great potential in the commercialization of organic solar cells(OSCs)due to their advantages in the manufacturing process.However,high-performance donor polymers are...Comprehensive Summary,Non-halogenated polymers have great potential in the commercialization of organic solar cells(OSCs)due to their advantages in the manufacturing process.However,high-performance donor polymers are limited to a small amount of building blocks.Herein,we utilize as building block 4H-dithieno[3,2-e:2',3'-g]isoindole-4,6(5H)-dione(DTID)to design and synthesize a relevant non-halogenated polymer PBTID for active layers in OSCs.PBTID exhibits a strong absorption in the wavelength range of 400—600 nm with a distinctly wide optical bandgap of 2.06 eV,a low-lying highest occupied molecular orbital(HOMO)energy level of−5.53 eV.In addition,this polymer has a very strong aggregation effect in solution and could form nanoscale fibrils in the neat film.Consequently,when blended with the non-fullerene acceptor Y6,the devices achieve a prominent PCE of 15.8%with a high Voc of 0.87 V.The Voc and PCE values are one of the highest values in the non-halogenated polymer donor-based OSCs reported to date.展开更多
Polythiophenes(PTs)are prospective polymer donors for large-scale manufacturing and industrialization owing to their simple structures and low synthetic cost.However,the fabrication of PT solar cells depends on highly...Polythiophenes(PTs)are prospective polymer donors for large-scale manufacturing and industrialization owing to their simple structures and low synthetic cost.However,the fabrication of PT solar cells depends on highly toxic chlorinated solvents,and less research has been done on the use of more environmentally friendly non-halogenated solvents.Herein,highly efficient PT solar cells based on top-performance polythiophene,P5TCN-F25,processed from a non-halogenated solvent are reported by delicate aggregation control.A power conversion efficiency of up to 15.68%was achieved by depositing the active layer from a hot o-xylene solution,which is the record efficiency of non-halogenated processed PT solar cells up to date.The appropriate solution temperature is beneficial to the formation of ordered polymer stacking and desirable phase separation size,which thereby contributes to enhanced charge transfer efficiency,more balanced hole/electron mobility,and reduced trap-assisted recombination.These results provide valuable implications for improving the efficiency of PT solar cells via environmentallyfriendly processing.展开更多
A double-cable conjugated polymer DCPIC-BO is designed via introducing a long-branched alkyl chains 2-buthyloctyl into the acceptor side unit.Compared with the double-cable polymer(DCPIC-EH)with the 2-ethylhexyl alkyl...A double-cable conjugated polymer DCPIC-BO is designed via introducing a long-branched alkyl chains 2-buthyloctyl into the acceptor side unit.Compared with the double-cable polymer(DCPIC-EH)with the 2-ethylhexyl alkyl chains,the solubility of the DCPIC-BO in non-halogen solvents is substantially improved.Therefore,a power conversion efficiency(PCE)of 9.77%can be obtained by the devices processed from o-xylene at 40℃,while the DCPIC-EH cannot be processed due to its poor solubility under this condition.Moreover,PCEs of 10.10%for small-area(0.04 cm^(2))devices and nearly 9%for devices with an area of 1 cm^(2) are achieved using a non-halogenated solid additive in o-xylene,realizing the"absolutely halogen-free"OSC fabrication.展开更多
基金the DS&T and NRF of SA(Coal Research Chair Grant No.86880)for funding this project.
文摘The coal combustion in cast-iron stoves leads to health hazards and air pollution.In this study the CO,SO2,NOx,PM and VOC emission concentrations were measured whilst combusting four fuel particle sizes(15,20,30,and 40 mm)as well as a composite of the sizes(all pre-devolatilized at a temperature of 550C)in a cast-iron stove.The results were compared to their raw coal analogues to evaluate the emission performance of each fuel type.Emission factors for NOx and SO2 were found to depend on the fuel nitrogen and sulphur contents in the coal and the combustion conditions used during pyrolysis.The PM,SO2 and VOC emissions show a strong dependence on the ash percentage and volatile matter yields,which both increased with increasing particle size.In addition,the PM,SO2 and VOC missions were found to only depend on particle size on a mechanistic level.The VOCs and PM emission factors are inversely correlated with particle size.The results from this study offer insight into the combustion environment in the Falkirk Union No 7 cast-iron stove as well as how this environment applies to low smoke fuels.The work contributes to the emission and performance inventories from South African domestic coal combustion in this stove used in informal settlements.
基金the Partnership for Skills in Applied Sciences,Engineering and Technology(PASET)-Regional Scholarship Innovation Fund(RSIF)(World Bank PASET No.IP22-15)supported by the National Research Foundation(NRF)(NRF-2021R1A2C2091787 and NRF-2022M3H4A1A03076280)+1 种基金the Korea Research Institute of Chemical Technology(KRICT)of the Republic of Korea(No.KS2422-10)the National Research Council of Science and Technology(Grant No.Global-23-007)of Republic of Korea。
文摘The interfaces between the inorganic metal oxide and organic photoactive layer are of outmost importance for efficiency and stability in organic solar cells(OSCs).Tin oxide(SnO_(2))is one of the promising candidates for the electron transport layer(ETL)in high-performance inverted OSCs.When a solution-processed SnO_(2)ETL is employed,however,the presence of interfacial defects and suboptimal interfacial contact can lower the power conversion efficiency(PCE)and operational stability of OSCs.Herein,highly efficient and stable inverted OSCs by modification of the SnO_(2)surface with ultraviolet(UV)-curable acrylate oligomers(SAR and OCS)are demonstrated.The highest PCEs of 16.6%and 17.0%are achieved in PM6:Y6-BO OSCs with the SAR and OCS,respectively,outperforming a device with a bare SnO_(2)ETL(PCE 13.8%).The remarkable enhancement of PCEs is attributed to the optimized interfacial contact,leading to mitigated surface defects.More strikingly,improved light-soaking and thermal stability strongly correlated with the interfacial defects are demonstrated for OSCs based on SnO_(2)/UV cross-linked resins compared to OSCs utilizing bare SnO_(2).We believe that UV cross-linking oligomers will play a key role as interfacial modifiers in the future fabrication of large-area and flexible OSCs with high efficiency and stability.
基金Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant(20214000000650)National Research Foundation(NRF)grant(2022R1A2B5B03001761)funded by the Korea government.
文摘Polymer solar cells(PSCs)with high power conversion efficiency(PCE)and environment-friendly fabrication are the main requirements enabling their production in industrial scale.While the use of non-halogenated solvent processing is inevitable for the PSC fabrication,it significantly reduces the processability of polymer donors(PDS)and small-molecule acceptors(SMAs).This often results in unoptimized blend morphology and limits the device performance.To address this issue,hydrophilic oligoethylene glycol(OEG)side-chains are introduced into a PD(2EG)to enhance the molecular compatibility between the PD and L8-BO SMA.The 2EG PD induces higher crystallinity and alleviates phase separation with the SMA compared to the reference PD(PM7)with hydrocarbon side-chains.Consequently,the 2EG-based PSCs exhibit a higher PCE(15.8%)than the PM7-based PSCs(PCE=14.4%)in the ortho-xylene based processing.Importantly,benefitted from the reduced phase separation and increased crystallinity of 2EG PDS,the 2EG-based PSCs show enhanced thermal stability(84%of initial PCE after 120 h heating)compared to that of the PM7-based PSCs(60%of initial PCE after 120 h heating).This study demonstrates the potential of OEG side-chain-incorporated materials in developing efficient,stable,and eco-friendly PSCs.
文摘The fibred magnesium hydroxide from the bracite was treated with a surface active agent. The modified fibred magnesium hydroxide as flame-retardant, boric acid, barium stearate, polydimethyl siloxane fluid, vinyltriethoxysilane as synergists of the flame-retardant were added to polyene resin. The flame-resistance polyene material prepared meets the requirements of EWCZ-6287-1. (Author abstract) 2 Refs.
基金supported by the National Natural Science Foundation of China(NSFC)(No.51973146)the Shandong Provincial Natural Science Foundation for Distinguished Young Scholars(ZR2022JQ09)Collaborative Innovation Center of Suzhou Nano Science&Technology.
文摘Comprehensive Summary,Non-halogenated polymers have great potential in the commercialization of organic solar cells(OSCs)due to their advantages in the manufacturing process.However,high-performance donor polymers are limited to a small amount of building blocks.Herein,we utilize as building block 4H-dithieno[3,2-e:2',3'-g]isoindole-4,6(5H)-dione(DTID)to design and synthesize a relevant non-halogenated polymer PBTID for active layers in OSCs.PBTID exhibits a strong absorption in the wavelength range of 400—600 nm with a distinctly wide optical bandgap of 2.06 eV,a low-lying highest occupied molecular orbital(HOMO)energy level of−5.53 eV.In addition,this polymer has a very strong aggregation effect in solution and could form nanoscale fibrils in the neat film.Consequently,when blended with the non-fullerene acceptor Y6,the devices achieve a prominent PCE of 15.8%with a high Voc of 0.87 V.The Voc and PCE values are one of the highest values in the non-halogenated polymer donor-based OSCs reported to date.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(2022B1515120008)the Guangdong Innovative and Entrepreneurial Research Team Program(2019ZT08L075)+1 种基金the National Natural Science Foundation of China(22275058,U20A6002)supported by the National Research Foundation of the Republic of Korea(NRF)grant funded by the Republic of Korea Government(MSIP)(2021R1A2C3004202)。
文摘Polythiophenes(PTs)are prospective polymer donors for large-scale manufacturing and industrialization owing to their simple structures and low synthetic cost.However,the fabrication of PT solar cells depends on highly toxic chlorinated solvents,and less research has been done on the use of more environmentally friendly non-halogenated solvents.Herein,highly efficient PT solar cells based on top-performance polythiophene,P5TCN-F25,processed from a non-halogenated solvent are reported by delicate aggregation control.A power conversion efficiency of up to 15.68%was achieved by depositing the active layer from a hot o-xylene solution,which is the record efficiency of non-halogenated processed PT solar cells up to date.The appropriate solution temperature is beneficial to the formation of ordered polymer stacking and desirable phase separation size,which thereby contributes to enhanced charge transfer efficiency,more balanced hole/electron mobility,and reduced trap-assisted recombination.These results provide valuable implications for improving the efficiency of PT solar cells via environmentallyfriendly processing.
基金supported by Beijing Natural Science Foundation(Nos.JQ21006 and 2212045)National Natural Science Foundation of China(NSFC,Nos.52073016 and 92163128)+1 种基金supported by the Fundamental Research Funds for the Central Universities(Nos.buctrc202111,buctrc201828 and XK1802-2)the Opening Foundation of State Key Laboratory of Organic-Inorganic Composites of Beijing University of Chemical Technology(No.oic-202201006).
文摘A double-cable conjugated polymer DCPIC-BO is designed via introducing a long-branched alkyl chains 2-buthyloctyl into the acceptor side unit.Compared with the double-cable polymer(DCPIC-EH)with the 2-ethylhexyl alkyl chains,the solubility of the DCPIC-BO in non-halogen solvents is substantially improved.Therefore,a power conversion efficiency(PCE)of 9.77%can be obtained by the devices processed from o-xylene at 40℃,while the DCPIC-EH cannot be processed due to its poor solubility under this condition.Moreover,PCEs of 10.10%for small-area(0.04 cm^(2))devices and nearly 9%for devices with an area of 1 cm^(2) are achieved using a non-halogenated solid additive in o-xylene,realizing the"absolutely halogen-free"OSC fabrication.
